Rubber compound and material for use in making same.



EBENEZER, W. STRAIN, OF PHILADELPHIA, PENNSYLVANIA.

RUBBER COMPOUND AND MATERIAL FOR USE IN MAKING SAME.

Specification of Letters Patent.

Patented Dec. 31, 1907.

Application filed October 30. 1905. Serial No. 285.040.

To all whom it may concern:

Be it known that I, EBnNnznn W. STRAIN, citizen of the United States, residing at 7 Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented new and useful Improvements in Rubber Compound and Material for Use in Making Same, of which the following is a specification.

The object of this invention is to profi'ide a rubber compound which shall possess all of theproperties of rubber and which, in add ition, will not be deleteriously affected by the contact therewith of oils, thereby presenting a compound particularly serviceable for use .in bearings, and for similar applications, where lubricants are employed.

It is well known to the rubber industry that petroleum and its products are solvents of rubber and very destructive to manufactured goods, but I have discovered that cer tain products of asphaltic petroleums, when prepared as hereinafter described, are nonsolvent of rubber unless high temperatures are applied. These products, however, of themselves-not only have no affinity for rubber, but when combined with it destroy, to a great extent, the elastic properties thereof and render it undesirable for use except for filling.

In proceeding according to my invention I first take a crude asphaltic petroleum and eliminate the'volatile. constituents thereof by distillation, after, which the remaining heavy products are also distilled and refinedv by the ordinary methods known to the trade, leav ing in the still a bitumen in some respects resembling black wax, and which, when blown in the still by the usual method employed by oil refiners, produces an elastic bitumen that is pliable at low temperatures. This bitumen will combine with rubber at high temperatures, varying from 250 F. to 350 F., but, as stated above, is deleterious in its effect when used in a raw state. To make this product valuable for use with rubber,

, I .combine with the bitumena product of the sap of pine or resinous trees, known to the trade as virgin dip or gum thus; or I may employ, in lieu of either of the latter, the res- I inous matter. left at the still after the spirits of turpentine have been eliminated, which is known to the trade as rosin pitch. All of these last-mentioned substances contain acidshaving an affinity for rubber, and when combined with the before-mentioned bitumen produce a com ound which may be readily combined wit rubber, resulting in the production of a rubber, compound possessing the properties abovc'noted.

Instead of using the bitumen and virgin dip, or gum thus as first compounded, I may use the distilled roduct resulting from this compound, as ereinafter described. The asphaltic bitumen is a solid, gummy,

waxy substance, while the distillate there-' from is a soft semi-fluid gummy substance, substantially the same as the bitumen, except that the distilling removes a portion of the carbon, no paraflin crystals being formed by the distillation. The bitumen, and the distillate therefrom, are substantially the same in the principal chemical constituents.

In practice I take eighty to ninety per cent. asphaltic base bitumen and ten to twenty per cent. of oxidized hydro-carbon of the terpene series, such as virgin dip or gum thus, and place these two substances in a kettle and subject them to a temperature of about 325 F. After the ingredients are thoroughly combined the product is then ready for use to combine with rubber. If preferred, however, I may place the bitumen and virgin dip, or gum thus, in a still, instead of in a kettle, and, after a temperature of 325 has been reached, continue the operation at a still higher temperature sufficient to distil the whole product together, and the resulting distillate can then be combined with rubber, with the exce tion of the product first coming over, which is a volatile solvent of rubber.

As' stated above, I may use rosin in place of the virgin dip or gum thus, but either of the latter is preferred.

It may be explained that virgin dip is the first run of sap from a tree, while gum thus is the sap from the tree in the later years of its life. The addition of the virgin dip or gum thus, or rosin produced from the same, imparts to the petroleum an affinity for rubber, and prevents 'the shortening of the elastic properties natural in rubber when petroleum products are combined therewith.

So far as I am aware, the residue from asphaltic base petroleum, as made within the past two years, is unlike any made in previous years, owing to the different character of the crude petroleum and a process results in the production of a bitumen of a rubberlike, gummy and Waxy character, one which is pliable at very low temperatures and which does not fly into fragments under a blow, as

does ordinary arafiin base bitumen. The

process referre to resultsgin partially oxidizmg the bitumen, While it lS'lIl the still, at a high temperature; thereby rendering it proof aglainst oxidation at ordinary temperatures. T e distillate from this product is readily,

oxidized and vulcanized, especially when in combination with resinous matters for which .particu ar locality, except so far that it 1s bitumen from asphaltic etroleu-m.' I do not limit m self to the use 0 petroleum from an essential that in the use of-such a substance I obtain therefrom a bitumen. As an illustration I might mention that the asphaltic petroleum obtained from the State of Texas yields a'bitumen satisfactory for my purpose.

. stages Letters Patent, is

y 1. A composition of matter comprising the bitumen from asphaltic petroleum and rub- ,jber.

' 2. A composition of matter comprising oxidized bitumen from aspha'ltic petroleum and rubberl 3. A composition of matter comprising the bitumen from asphaltic petroleum and a resinous sap. t w

4. A composition of matter comprising the bitumen from asphaltic petroleum and VIIgiII,

dip or gum-thus.

p n testimony whereof I have hereunto set my hand in'presenoe of two subscribing Witnesses.

I Witnesses? MARGARETHA Voo'r, FRANK R: STRAIN.

I-Iavin this fully described my invention, I What I c aim as new and desire to secure by EBENEZER W. s'rn iN. I 

